The nations of the world are adopting international standards relating to packaging of dangerous goods for transportation, at the urging of organizations such as the International Air Transport Association (IATA). These international standards under the International Civil Aviation Organization (ICAO) require that the dangerous goods be contained within a pressure vessel. A pressure vessel that represents the state of the art is U.S. Pat. No. 5,167,344 which issued to Saf-T-Pak Inc. in December of 1992. This pressure vessel is a polymer plastic container that has an annular collar that extends outwardly and downwardly from sidewalls adjacent a top rim. The annular collar has a threaded exterior surface to which a closure lid with mating threads is secured. The threaded connection, as described, is insulated from inward and outward flexing of the sidewalls of the container which invariably results when the container is exposed to differentials in pressure.
As diagnostic specimens may contain infectious substances, IATA has indicated that all diagnostic specimens should be treated as dangerous goods and transported within a pressure vessel. The cost of complying with ICAO regulations with existing polymer plastic containers is prohibitive. The number of diagnostic specimens transported annually in the United States alone is in the billions. Some of the larger laboratories in the United States perform diagnostic testing on in excess of a quarter of a million diagnostic specimens per day.